14
Table 5 — EconoMi$er Switchover
Control Strategy
*Must be selected manually.
DRY BULB CHANGEOVER SET UP — Determine the dry
bulb changeover set point from Table 6. The settings are A, B,
C and D. Locate the ECON SP potentiometer and set the dry
bulb changeover set point. See Fig. 16. When the OAT is above
this set point, the damper is limited to minimum position
setting.
If a potentiometer fails, its setting will default to the values
in Table 7.
Table 6 — Changeover Set Points
*Field-installed accessory.
Table 7 — Default Potentiometer Settings
ECONOMI$ER
SWITCHOVER
STRATEGY
SENSORS REQUIRED
Outdoor Air
Temperature
Outdoor Air
Enthalpy
Return Air
Temperature
Return Air
Enthalpy
Dry Bulb
X
Single
Enthalpy
X
Differential
Temperature
X
X
Differential
Enthalpy*
X
X
SETTINGS
A
B
C
D
Dry Bulb (°F)
73
69
66
63
Single Enthalpy* (Btu/lb)
27
25
24
22
Differential Temperature*
(°F, Not Adjustable)
2
2
2
2
Differential Enthalpy*
(Btu/lb, Not Adjustable)
1
1
1
1
POTENTIOMETER
DEFAULT SETTING
CO
2
SP (PPM)
1,000
MECH CLG LOCKOUT
50 F
ECON SP
D
MIN POS (%)
20
LEGEND
*OAT sensor shipped with EconoMi$er option. OAH, RAT, RAH and CO
2
are field-installed accessories.
Fig. 23 — Typical EconoMi$er Sensor Wiring
COM
—
Common
DAT
—
Discharge Air Thermistor
DM
—
Damper Motor
GND
—
Ground
OAH
—
Outdoor-Air Enthalpy Sensor
OAT
—
Outdoor-Air Temperature Sensor
POT
—
Potentiometer
RAH
—
Return-Air Enthalpy Sensor
RAT
—
Return-Air Temperature Sensor
REM
—
Remote